# WM_GetAllowedChannel

## C Specification

      #include <nitro/wm.h>

      u16 WM_GetAllowedChannel( void );

## Description

Gets the channels that should be used in wireless communications

This function is executable only when WM is in the IDLE state. For example, if `0x1041` is returned, channels `1`, `7`, and `13` will have the permission to be used.

Use this function to find channels that are allowed to set the channel parameter in the `WM_SetParentParameter` function. Use `WM_MeasureChannel` to check the radio conditions of each channel.

When scanning for the parent device as the child device with `WM_StartScan`, the parent device should be active on one of the channels that is obtained with this function. This will allow the narrowing down of the channels that should be scanned. However, this limit does not exist in infrastructure mode.

## Caution

When a value of 0 is returned to this function, there are no channels that should be used. In other words, it will display that wireless communications should not be performed. Be aware that there is the possibility that a value of `0` will be returned if there was a console produced for a region where wireless communication is prohibited.

## Arguments

None.

## Return Values

Returns the bitmask specifying the group of channels that are allowed to be used (between 1 and 14).

Responds in order from lowest to highest bit (channel 1, channel 2, et al.) and returns `0x8000` if WM is unaccessible (e.g. before initialization).

## See Also

`WM_SetParentParameter`, `WM_StartParent`, `WM_MeasureChannel`, `WM_StartScan`

## Revision History

10/27/2004 Revised description of error values in "Return Values"
09/25/2004 Added and revised descriptions
08/20/2004 Initial version